Grinding machine



3 SHEETS-SHEET I flzz/enfor. Wa Zzer (f 577221 72 Jan. 2, 1923. 1,440,639

w. I. SMITH.

' GRINDING MACHINE. FILED JUNE 8, 1921 3 SHEEITSSHEET 2 1 Patented Jan. 2.. 1923.

iTE

OFFICE... I

WALTER J SMITH, ST. LOUIS, MISSOURI, ASSIGNOR '10 McQUAY-NORRIS MFG.

Q]?v ST.LOUIS, MISSOURI, A CORFORATIQN OF MISSOURI. I

GRINDING, MA-CHINE.

Application filed June 8,

evenness due to 'casting, although I do not wish to-be understoodas restricting the application of the invention'to piston rings, as it may be employed with equal advantage to any article of manufacture wherein a given surface is subjected to a grinding operation to make said surface conform" in contour with an opposite surface in order to producean article of uniform thickness.

It is well understood in the art that when an article in the shape of a ring, such as a piston'ring, is cast, it often happens thatthe pressure of the metal against the outer wall of the mould distends the mouldin places due .to the fact that thesand, not being sufficiently compacted, gives way to a certain extent on the outside. .The sand on the inside of the mould is more'compaot, having been confined by the" inner wall of the pattern, and successfully resists the pressure of the molten metal, resulting in a casting that is perfectly true along its inner wall or sur-' The fact that the inner surface of'the.

face. ring is true-is availed of by myinvention to make the outer surface also true, the same being made to conform in contour with the inner surface, thusproducingaring of absolutely uniform thickness.

bettera'pparent from a detailed description v of the-same in connection with the; accompanying drawings in which Figure 1 is a perspective view of my improved grinding machine; Fig. 2 is an end elevation thereof; Fig. 3 is a top plan view of the same; Fig. 4 is an enlarged sectional detail taken on the line 4r 4' of Fig. 3; Fig. 5 is a side elevation of the feed mechanism for rotating the ring past the grinding 1-921. Serial No. 476,026.

i wheel; Flg. 6 1S avertioalcross-section taken on the line 6-6 of Fig. 3, parts being left in elevation; Fig. 7 is a fragmentary per spective View of the spring controlled slide and abutment post whereby the-slide is released when the work-table ispulled for removing the ground ringyFig. 8'is a vertlcal section taken on the zig-zag line 8-8 of F 5; Fig. 9 is an enlarged sectional detail of the .ball bearing abutment roller; and Fig. 10 is a face view. of a piston ring to be ground showinggreatly'exaggerring.

Referrin to the drawings S represents a standard, (1r a-grinding wheel mounted in the bearing B, and P a drive pulley driven b belt B. from a suitable source of'power. supporting rod R projects from the side of the standard S and a bracket S is adjustably clamped onto the rod B, said bracket being provided with an adjustable slide S" to which is bolted a lug'L carrying a suit able base-plate M. The parts thus far described are well known in the art constituting the elements of an ordinary grinding machine,and are availed of by me in the application of my improvement about .to be de-' scribed.

A substantially circularwork-table 1 is supported on the base-plate M in close proximity to the grinding wheel G and held in position on the base-plate by guide-studs 2, 2 operating through slots 3, 3 and screwed into the base-plate. The periphery of the work-table opposite the grinding wheel has a tongue formed on it, and on either side thereof are plane surfaces 5, 5. A U-'shaped plate 6 is secured to the edge of the base M opposite the tongue 4, andv an arm 7 is secured to the work-table over the tongue 4,

said arm being'ro cessed in the work-table and having a downwardly bent finger 8 formed on its free end through which is screw-threaded an adjusting screw 9, the inner end of the screw bearing'against the plate 6. A lock-nut 10 is passed over the screw 9 to maintain the same in the adjusted position. Projecting from the plane surfaces 5, 5 of the Work-table are {studs 11, 11

.on which are coiled springs 12, 12, the studs traversing the U-plate 6 and the springs being confined between. the edge of the worktable and plate 6 so as to urge the worktable'toward the grinding wheel and main- :ited'the irregular outer periphery of the a purpose presently Thework-table 1 is'provided'wlth a ball.

' tain the screw 9 in abutting relationwith' .the:plate ed' on the base M adjacent the rear edge I thereof and iszscrewed-to the arm 7 at an 6. A lever 13 is pivotally mountintermediate point 14 and projects for wardly a suflicient-distanoe so that it may be the operator for conveniently oscillated by to appear.

bearing 15 contiguous to the grinding wheel G, the ball bearing being mounted on a stud grooves 18 v16 a short distance inwardly from the periphery bearing 15 but terminating short of said bearing, however, and positioned in the grooves 18, 18 are slides 19, 19' respectively, said slides carrying near their inner ends rollers 20, 20 mounted on studs 21, 21' respectively. Each of the slides has. a slot. 22 formedin it near its outer end which is traversed by a stud 23 secured into the table 1. The stud 23 in the slide 19 is used. as a clamping screw to securely hold said slide in its adjusted position, while the ,stud 23 in the slide 19 is used merely as a confining element to hold it in its slot 22 while permitting the slide to reciprocate. A finger 24 projects outwardly from the edge of the table 1 and has its extremity 24 bent over so as to come substantially in line with theslide 19' and a coiled spring 25 is secured at one end to the slide 19' and at the other end to the bent finger 24, said spring exerting an outward pull on the slide 19.- A slide 26 is mounted in a slot 27 in the' base' M near the front edge ofthe base, said slide being ,adjustably secured in the base by a stud 28 traversing a slot 29 inthe slide and secured in the base. The slide 26 carries a stop-pin p projecting from its upper surface, said stop-pin being in line with the slide 19 and spaced a short distance from the outer end thereof.

A bracket 30 is secured at the front of the base M and is provided with a forwardly projecting. flange 31 which has a cylindrical socket 32 depending from it, the lower part of said socket being screw-threaded to receive an adjusting screw 32' for regulating the tension of a spring 33' contained in the socket between the screw and a: round-nosed tumbler 34. A block 35 is pivotally mounttated. The block be moved toward'or away from degress apart at the periphery space 17 to correspond with .of the rings he is working on.

ed on a bolt 36,adjustaliilyv secured in a slot 37 in the bracket 30,\the. upper'part of the block being bored to providea bearing for spindle 38 maintained inthe block by collars 39, 39' on the spindle, said spindle carrying on its inner end a feed-roller 40 milled on its periphery and having a crank 41 on its outer end whereby the roller may be ro- 35 has a pair of continuous grooves 42, 42, formed on its under side above the tumbler 34, said grooves being so spaced that when the block is in a horizontal position (Fig. 5) the tumbler 34 will bear against the inclined wall a of groove 42 and urge the roller downwardly, and when the crankhandle is pressed will cam the tumbler into the socket until it passes the ridge 6 at which moment the spring 33 will urge the tumbler-upwardly into the groove 42', the block being maintained in an inclined osition with the roller raised (dotted position Fig. 5).

The operation of my invention may be described as follows:

We will assume that a ring 50 is imperfectly cast having irregular swells 51, 51 at points in its periphery due to the giving way of the sand whe'n the metal is poured as abovedescribed. Now this ring would ordinarily be rejected as it is worthless as a piston ring unless the outer periphery can be ground to correspond in contour with the inner periphery to produce a ring of even thickness all around, so essential to give to the finished ring uniform tension against the cylinder walls at all points. In accomplishing this object in my machine I avail myself of this true inner periphery of the ring by causing the outer periphery of the ring to pass over a grinding surface while the inner periphery is maintained in contact with a fixed abutment spaced from the grinding surface a distance corresponding to the thickness of the finished ring. The operator first adjusts the width of the the thickness This, as has been explained, is done by turning the screw 9 in the proper direction. Then the slides 19, 19' are set so that when the ring is placed on the work-table in engagement with ball bearing roller 15, the rollers 20, 20 will bear against the inner surface of the ring, the roller 20 exerting pressure against the ring under influence of spring 25. The operator now turns the crank 41, whereupon the feed roller 40, bearing against the side face of the ring under influence of spring 33, will rotate the ring on the work-table, said crank being turned until the ring has been rotated one complete turn. By this time the entire outer periphery of the ring has passed over the rapidly revolving grinding wheel and all the irregularities have been ground off so downwardly the wall a that the thickness of the ringat all points in its circumference is the same. The operator now bears down on the crank 41, raising the wheel 40 off the ring, and throws the lever 13 to the left, pulling the work-table away from the grinding wheel over the tension of springs 12, 12. As the work-table moves outwardly the outer end of slide 19 will engage the pin 39 which arrests the slide, the work-table continuing in its movement a short distance further. The roller 20 is, of course, arrested with the slide 19 and the ring 50 continues on a short distance with the work-table thus effecting a separation of the ring and roller 20 so that the ring may be removed fromthe worktable and another placed thereon, when the operation is repeated. When the slides 19,

19' and work-table 1 have been once ad-' justed for a given size of ring they do not again have to be adjusted unless a different sized ring is ground.

It will be observed that the base M is shown inclined in the drawings, the, ring being ground on the bias, which results in a better grinding action than if the ringsprecise details of construction herein shown.

Having described my invention, Iclaim:

1. In a machine for grinding piston rings, a grinding element, a work-table adjacent thereto, a ball bearing abutment member on the work-table against which the inner periphery of the ring is adapted to bear, rollers slidably mounted on the work-table for holding the ring in engagement with the abutment member, means for maintaining the abutment member a predetermined distance from the grinding element, means for rotating the ring past the abutment member, and means for releasing the ring from the rollers.

2. In a machine of the character described, a grinding element, a work-table adjacent thereto, an abutment member fixed on the Work-table, means for adjusting the abutment member to and from the grinding element, a pair of work-holding members adapted to maintain the work in engagement with the abutment member, and means for feeding the Work past the grinding ele-' ment.

3. In a machine of the character described, a grinding element, a work-table adjacent thereto,-an abutment member fixed on the work-table, means for adjusting the abutment member to and from the grinding element, a pair of work-holding members adapted to maintain the work in engagement with the abutment member, means for releasing one of said work-holding members from the work, and means for feeding the work past the grinding element.

a. In a machine. of the characterdescribed, a grinding element, a work-table adjacent thereto, an abutment member fixed on the work-table, means for adjusting the abutment member to and fro-m the grinding element, a pair of work-holding members adapted to maintain the work in engagement with the abutment member, means for withdrawing the work-table fro-m the grinding element for disengaging the work, and means for feeding the work past the grinding element.

5. In a grinding machine, a grinding element, a work-table adjacent thereto, an

abutment member on the work-table, a pair a of work-holding'members adapted to maintain the work in engagement with the abutment member, and means for feeding the' work past'the grinding element.

6. In a grinding machine, a grinding element,-a work-table adjacent thereto, an abutment member on the work-table, a pair of work-holdingmembers adapted to maintain the work in engagament with the abutment member, means for adjusting said work-holding members to the Work, and means for feeding thework past the grinding element.

In testimony whereof I hereunto aflix my signature.

WALTER J. SMITH. 

